Reversing gear for washing machines and similar reversible machines



Sept. 26, 1933. E. SCHU'RMANN Filed March 26, 1930 Patented Sept. 26, 1933 UNITED STATES- PATENT OFFICE CHINESANDS I omNEs Eugen Schiirmann,

Application Maren 26, 1930, d in' Germany April REVERSIBLE MA- Dusseldorf Germany- Serial No.'439,071,

the driving belt itself of the reversing gear which belt drives a driving pulley of the shifting mechanism, this driving pulley taking part in the to and fro shifting motion of the driving belt.

My invention has for its object to permanently impart to the driving belt in a simple and easy manner and entirely automatically the required tension without application of a special belt spanner, which object is obtained substantially by the fact that the shifting mechanism is freely swlngingly suspended from a shaft extending in parallelism to that of its driving pulley in such a manner that it is capable of tensioning the belt by gravity.

In order that my invention can be more readily understood, a preferred embodiment of the same is illustrated by way of example in the accom drawing as applied to a washin machine. In this drawing Figure 1 is an elevation, partly in vertical and longitudinal section, of the parts concerned of the machine,

Figure 2 is a vertical cross section on line 2-2 of Figure 1, seen from the left, and

Figure Bis a detail of the shifting mechanism shaft to be alternately set left-hand rotation, of a washing machine. A

' fixed shaftC is freely supported on the mounting of the machine in parallelism to shaft A, on which shaft C is mounted "for rotation a tubular shaft D. This shaft D has rig dly fixed on its,righthand end a pulley E and on its left-hand end a pinion 2 whilst beside the pulley E a loose pulis rotatably mounted thereon, and besides through the intermediary On the left-hand end of In this manner the the latter a pulley G of a tubular shaft H. shaft H is fixed a pinion g pulley E is in rigid connection with pinion e and, 5 on the other hand, puley o with pinion a COIXIIBOD.

same direction of rotat1on by one Two spur wheelsa a are rigidly mounted on the free end of the drum shaft A by meansof a wheel sta wheel a being directly in mesh with pinion g whilst wheel a? is indirectly in mesh with pinion e by means of an intermee diate wheel a rotatably mounted 03 a journal e fixed on the mounting B of the machine.

The wheels 9 a a a e thus form a reverted wheel'system the outer wheels of which rotate, in inverse direction. Therefore when the pulleys E and'G rigidly connectedwith these two wheelsare alternately driven in the same direction of rotation, the drum t V the one case a right-hand rotation and in the other case a left-hand one.

The pulleys E and G are always driven in the open belt K from the motor pulley L, the to and fro shifting motion of belt K being produced automatically driving pulley M of which receives itsrotation directly from the very belt K and takes part in the shifting motion of the latter.

The belt shifting mechanism substantially consists of a box-shaped shifting frame N and a casing 0 located immediately opposite frame N. The latter is adapted to be shifted horizontally on two guide bars P fast on a supporting arm W in parallelism to the gear shaft C, the arm W- being D that includes the above reverted extension b being coaxial with shaft C. The casing 0 can be shifted and fixed on two guide bars. Q as described hereinafter. The bars Q are rigidly connected to the guide bars P by means of a bail Q The shaft carrying the driving pulley M is mounted for rotation in the lateral wallsof the shifting frame N the rotation of which pulley is transmitted by aworm m to a worm wheel 1n and from the latter by a pinion m coaxial therewith, to another pinion m. This latter pinion carries a crank pin m which projects into the casing 0 and is adapted to engage a guide 0 provided in casing 0 and having the shape of a crank guide enlarged toward both ends, see best Fig- 1118-3;

In the position of rest illustrated in Figure 1, of the described drum shaft driving gear the casits upper position in which the walls of the crank guide 0 are out of the orbit of latter has no effect on them. i should be thrown into operation, the casing O is no shifted into its lower position shown in Figure 3 line of the crank guide 0 coincides with the center of the crank circle of pin m and, as casing O is stationary, the rotary motion of pin m causes a to and fro shifting motion of the belt-shifting irame N. In this reciprocating'motion frame N carries with it a belt shifter n which is fixed thereon and alternately puts the belt K on the one or the other of the pulleys E and G. Due to the crank guide 0 being enlarged toward both ends, the shifting motion does not take place continually upon reversal but stepwise, because of the fact that the crank pin m then runs idly on a determined section of its orbit before engaging the opposite wall of the crank-guide 0 quently the respective driving action of each pulley lasts a certain period of time, asthe crank Tpin rotates only at a comparatively low speed.

Owing to the belt shifting mechanism being swingingly suspended itsweight exerts aturning moment about the axis it is suspended'from by which moment the pulley M is permanently urged onto belt K whereby the latter is automatically kept under the required tension. Under certaincircumstances it may be of advantage with respect to the location of th pulley L of the driving motor to increase the moment exerted by the weight of the controlling mechanism, this being obtained for instance by adequately providing a spring Z, as shown in dot and dash lines in Figure 2. Furthermore, it is able utilization Conse-- not necessary in any case that the supporting arm W isireely suspended coaxially with the pulleys 'E, G, but this free suspension can be established also from a separate shaft, such as shaft C shown in dot and dash lines in Figure 2 which is fixed on the mounting of the machine and extends in parallelism to gear shaft C. This arrangement would aiford under circumstances a more favorbelt shifting mechanism and a reduced structural extension of the gear. In all events my'new' arrangement aifords the possibility of permanently and entirely automatically keeping under tension the driving belt in the simplest possible manner without provision of a special belt spanner, whereby a considerable operation 01' the machine is obtained.

What I claim and desire to secure by Letters Patent isz- In a machine of the class described having a reversing gear with two driving pulleys, a single driving belt adapted to alternately drive one 01' said pulleys and an automatic belt shitting mechanism including a driving pulley in contact with the driving'belt of the reversing gear, the combination of the belt shifting mechanism with a shaft extending in parallelism to the shaft'oi' the driving pulley of said mechanism and an arm freely swingingly pivoted on said first-named shaft, said mechanism being mounted on said arm, the center of gravity of shifting mechanism lying outside a vertical plane going through the pivot-axis 01 said arm.

EUGEN SCHURMANN.

of the efl'ect of the weight of the simplification and reliable said arm together with the 

